The Wireless RS485 Modbus Converter enables seamless wireless communication for legacy Modbus devices that communicate via RS485. This converter allows users to convert any Modbus RS485 device into a wireless node, eliminating the need for long communication cables. The converter supports common Modbus read commands, such as reading holding registers and input registers, and provides several settings to optimize its functionality.
This Device should only be used to convert Modbus devices into wireless nodes and should NOT be used as a wireless RS 485 bridge. If you are looking for an RS485-Wireless bridge, please check out PR55-34.
Product Features
- Wireless Communication: Converts RS485 Modbus devices to wireless nodes.
- Supported Commands:
- Read Holding Registers (Function Code 03)
- Read Input Registers (Function Code 04)
- Power Supply: 5V to 24V DC
- Communication Settings: Network ID, Power Level, Retries, Baud Rate, RX Timeout, Boot Time, Slave ID, Number of Registers, Function Code
- Hardware Components: Radio Module, CPU, RS485 Port
- Enclosure Terminals: A, B, Power Positive, Power Negative
Device Working Principle
The converter consists of a radio module, a CPU, and an RS485 port. The device is powered through the provided screw terminals. Users can configure how frequently they want to read the Modbus device and which registers to read. Based on these settings, the device will query the specified registers at the user-defined intervals and compile the data into a package, sending it wirelessly.
Supported Read Operations:
- Read Input Registers
- Read Holding Registers
Device Settings
- Set Baud Rate:
- Configure the communication speed for the RS485 port.
- Set RX Timeout:
- Define the RS485 read/write timeout in milliseconds. By default, RS485 devices are in read mode. The timeout ensures the device waits for the specified duration before switching modes.
- Set Boot Time:
- Set the boot time in seconds to allow the sensor to initialize before reading data. For example, if the user wants to read the device every 30 seconds but requires a 2-second boot time, this setting will be configured accordingly.
- Set Slave ID:
- Assign the Modbus slave ID. Each Modbus slave device requires a unique converter, as this device cannot read from multiple slaves simultaneously.
- Check Number of Registers:
- Specify the number of registers to read, up to a maximum of 32 registers in one operation.
- Set Function Code:
- Choose between Function Code 03 (Read Holding Registers) and Function Code 04 (Read Input Registers).
Configuration and Operation
- Powering the Device:
- Connect the power supply to the terminals marked as Power Positive and Power Negative (5V to 24V DC).
- Connecting RS485:
- Connect the RS485 A and B terminals to the corresponding terminals on the Modbus device.
- Configuring Settings:
- Use the provided interface to set the baud rate, RX timeout, boot time, slave ID, number of registers, and function code.
- Reading Data:
- Once configured, the device will automatically read the specified registers at the defined intervals. The read values will be compiled into a single response and sent wirelessly. The response order will match the order of the requested registers.
Example Configuration
- Baud Rate: 9600
- RX Timeout: 1000 ms
- Boot Time: 2 seconds
- Slave ID: 1
- Number of Registers: 3 (e.g., 1, 3, 7)
node red — Node-RED should be utilized for configuring the device
